I have a list of over 500 people, and I want to have each one in the TO: field. However, I don't want the entire list visble to everyone. I also don't want to use bcc since many of the subscibers have emails blocked that don't have their address in the to field.

I know I could use a foreach and open and close sendmail each time, but for a list this big won't that take a long time? So, here's what I am thinking: have 1 sendmail connection open and loop through each address sending an email to a different person. Is this even possible?

Go to www.cpan.org and check out some modules in the Email category. There some modules like "Net::SMTP" and "Mail::Sender". These modules allow you to send email directly with PERL and without external executables like 'sendmail'. They work very well. I've used the "Mail::Sender" module to send e-mail from a script before.